Submission #929083

#	Time	Username	Problem	Language	Result	Execution time	Memory
929083		haru09	Global Warming (CEOI18_glo)	C++17	100 / 100	120 ms	6472 KiB

glo

#include<bits/stdc++.h>
using namespace std;
#define ll long long
#define fi first
#define se second
#define task "code"

const int ar=2e5+5;
const ll mod=1e9+7;
int n,x;
int a[ar];
int l[ar],r[ar];
vector<int> v;
int pos(int val)
{
    return lower_bound(v.begin(),v.end(),val)-v.begin()+1;
}
int bit[ar];
void update(int u,int v)
{
    int id=u;
    while(id<=n)
    {
        bit[id]=max(bit[id],v);
        id+=id&(-id);
    }
}
int get(int p)
{
    int id=p;
    int ans=0;
    while(id>0)
    {
        ans=max(ans,bit[id]);
        id-=id&(-id);
    }
    return ans;
}
int main()
{
    ios_base::sync_with_stdio(0);
    cin.tie(0);cout.tie(0);
    if (fopen(task".inp","r"))
    {
        freopen(task".inp","r",stdin);
        freopen(task".out","w",stdout);
    }
    cin>>n>>x;
    for (int i=1;i<=n;i++)
    {
        cin>>a[i];
        v.push_back(a[i]);
    }
    sort(v.begin(),v.end());
    for (int i=1;i<=n;i++)
    {
        int p=pos(a[i]);
        int dp=get(p-1)+1;
        update(p,dp);
        l[i]=dp;
    }
    for (int i=1;i<=n;i++) bit[i]=0;
    for (int i=n;i>=1;i--)
    {
        int p=n-pos(a[i]-x+1)+1;
        r[i]=get(p);
        p=n-pos(a[i])+1;
        int dp=get(p-1)+1;
        update(p,dp);
    }
    int ans=0;
    for (int i=1;i<=n;i++) ans=max(ans,l[i]+r[i]);
    cout<<ans;

}

Compilation message (stderr)

glo.cpp: In function 'int main()':
glo.cpp:45:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   45 |         freopen(task".inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
glo.cpp:46:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |         freopen(task".out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 13 / 13
• Subtask 4: 10 / 10
• Subtask 5: 20 / 20
• Subtask 6: 17 / 17
• Subtask 7: 25 / 25